(a) Field
The invention relates to a display device, and more particularly, to a display device including white pixels.
(b) Description of the Related Art
A display device such as a liquid crystal display (“LCD”) and an organic light emitting diode display (“OLED”) generally includes a display panel including a plurality of pixels including switching elements and a plurality of signal lines, a gray voltage generating unit generating a gray reference voltage, a data driver generating a plurality of gray voltages by using the gray reference voltage and applying a gray voltage corresponding to an input image signal among the generated gray voltages to a data line as a data signal, and the like.
The display device includes a self-emission display device including a light emission element capable of emitting light by itself and a light-receiving display device including a backlight.
As a representative example of the light-receiving display device, the LCD is one of the most common types of display devices currently in use. The LCD includes a display panel including a plurality of pixels and a backlight unit supplying light to the display panel. The display panel includes a liquid crystal layer having dielectric anisotropy and field generating electrodes such as a pixel electrode and a common electrode which generate an electric field in the liquid crystal layer. The pixel electrodes may be arranged in a matrix form and connected to the switching elements such as a thin film transistor (“TFT”) to sequentially receive data voltages for each row. The common electrode receives a common voltage. A desired image may be acquired by applying the voltages to the pixel electrode and the common electrode to generate an electric field in the liquid crystal layer and controlling the intensity of the electric field to control transmittance of light passing through the liquid crystal layer.
Two field generating electrodes such as the pixel electrode and the common electrode may be positioned on one display panel or may be provided on two display panels facing each other, respectively. When the display device includes two display panels, the pixel electrodes receiving the data voltage of the field generating electrodes and a plurality of TFTs are arranged in a matrix form on one display panel of two display panels facing each other, and color filters expressing basic colors such as red, green, and blue and a light blocking member which may prevent light leakage between the pixels may be disposed on the other display panel. Unlike this, the light blocking member may also be disposed on the same display panel as the pixel electrode and the TFT, and in this case, the color filters may be formed on the same display panel as the pixel electrode.
Such a light-receiving display device generally includes red pixels, green pixels, and blue pixels which may display images of three primary colors of red, green, and blue, respectively. Various color displays may be implemented by controlling luminance of each of the red pixels, the green pixels, and the blue pixels. However, since the red pixel, the green pixel, and the blue pixel include color filters, an amount of light emitted from the backlight is decreased while passing through the color filters, and as a result, the luminance of the image deteriorates. In order to solve the problem, white pixels which do not include color filters, other than the color pixels expressing the primary colors such as three primary colors, may transmit more light of the backlight than the color pixels having corresponding color filters associated therewith. That is, the white pixel does not include the color filter, and as a result, the luminance of the image may be increased.